Formula One owners Liberty Media have underestimated the task of running the sport and must be firm in setting out a vision for the future, according to Red Bull team boss Christian Horner.

Speaking to reporters before the 2019 cars are unveiled next week, Horner was also scathing of technical changes he said had been expensive to implement but would change little on track.

US-based Liberty, who took control two years ago, want closer racing and a more level playing field.

Liberty, led by chief executive Chase Carey, took control of F1 from Bernie Ecclestone in 2017

They have sought to make a more even playing field but have faced resistance from teams

‘I think they probably thought there was some very low hanging fruit there and I think it’s proved an awful lot harder than they perhaps thought,’ Horner said of Liberty’s initial approach to the sport.

‘You can window dress and promote a movie as much as you like, but if the movie has not got the substance and isn’t an exciting movie, people won’t watch it.’

The agreements between teams, the rights holders and governing body expire at the end of 2020 and Liberty’s ambitions include a budget cap and distributing revenues more equally, as well as technical changes so that cars can follow at close quarters and overtake more easily.

The detail has yet to be defined, however, with resistance from wealthy teams who have historically enjoyed special privileges.

Horner said Liberty had taken positive steps in areas such as esports, digital platforms and promotion, but they needed to set out a clear post-2020 blueprint.